Anti-CD66b (CEACAM-8, CEA-related cell adhesion molecule 8, CGM6, CEA gene family member 6, NCA-95,

Four members of the carcinoembryonic antigen family, CD66a, CD66b, CD66c, and CD66d, are expressed on human neutrophils. In neutrophils these proteins are activation antigens in that their surface expression is increased following stimulation. To examine their potential role in neutrophil signaling, the effects on neutrophil adhesion to human umbilical vein endothelial cells of a panel of well-characterized CD66 mAbs was tested. CD66a, CD66b, CD66c, and CD66d antibodies each increased neutrophil adhesion to human umbilical vein endothelial cell monolayers. This increase in neutrophil adhesion caused by CD66 antibodies was blocked by a CD18 antibody and associated with up-regulation of CD11/CD18 on the neutrophil surface. This increase in neutrophil adhesion required physiological extracellular calcium concentrations at or near the time of CD66 antibody binding to the neutrophil. The incubation of CD66 antibodies with neutrophils in the absence of calcium for 10 min before repletion of calcium resulted in no increase in neutrophil adhesion. The data suggest that CD66a, CD66b, CD66c, and CD66d antibody binding to the neutrophil surface triggers a transient activation signal that requires extracellular calcium and regulates the adhesive activity of CD11/CD18. Sequential desensitization experiments indicated that CD66a, CD66b, CD66c, and CD66d can each independently transmit signals in neutrophils. Gene ID: 1088, Gene Symbol: CEACAM8, Applications: Suitable for use in Immunohistochemistry, Fluorescence Microscopy and Flow Cytometry. Other applications not tested. Recommended Dilution: Fluorescence microscopy or Flow Cytometry: 1:50-1:100, Immunohistochemistry: 1:25-1-100. Frozen, Optimal dilution determined by the researcher. Positive Control: Bone marrow, Source: Ascites, Storage and Stability: May be stored at 4°C for short-term only. For long-term storage and to avoid repeated freezing and thawing, add sterile glycerol (40-50%), aliquot and store at -20°C or colder. Aliquots are stable for at least 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.